Muramasa was called "the most skillful smith but a violent and ill-balanced mind verging on madness". Muramasa blades were popularly believed to hunger for blood and to impel their warriors to commit murder or suicide. He may also be referring to the uchigatana Sengo Muramasa.

Tonbokiri is considered as one of the 3 best spears in Japan, while it's owner, Honda Tadakatsu was praised as the greatest samurai in history by Oda Nobunaga and Tokugawa Ieyasu. Thus, they were thought of as a dream team.